Method of welding



G. A. LUTZ METHOD OF WELDING Original Filed May 4, 1955 s Sheets-Sheet 1 INVENTOR 6'60 1?. Luzz ATTORNEY G. A. LUTZ METHOD OF WELDING Oct. 8, 1935.

s Sheets-Sheet 2 Original Filed May 4, 1953 INVENTOR 'eoj. L ufz ATTORNEY G. A. LUTZ METHOD OF WELDING Oct. 8, 1935 Original Filed May'4, 1933 3 Sheets-Sheet-3 QHHMMUI/IVI/ U m w x 1 w w u 3 Q k H m. 1 ll 0% I ATTORNEY Patented Oct. 8, 1935 UNITED STATES PATENT OFFICE METHOD OF WELDING Application May 4, 1933, Serial No. 669,341 Renewed February 27, 1935 9 Claims.

tions of metal stock are lapped one upon another 5 and welded together.

In accordance with my invention one marginal portion of metal stock or skelp is offset with respect to the adjacent metal thereof, as by bending or deflecting said portion, and another marginal portion of the stock to be welded is lapped on said ofiset portion, to a suitable distance; said lapped portions are then welded together, and the welded portions are pressed in such a way that the oifset portion is pressed or forced out wardly or laterally between the adjacent main portions of the stock or skelp, in substantial register with the latter, causing said main portions to move in directions away from one another to admit the offset portion therebetween, whereby the welded parts and the main parts of the stock may be brought into a desired or substantially uniform relation, such as in circular form. My invention is particularly adapted to welding the marginal portions of tubular metal stock or skelp for the production of lap-welded tubes or pipes having their circumferences substantially uniform. When said marginal portions of tubular stock are lapped a space is left between the longitudinal edge of one portion and an inset part at the offset marginal portion, whereby the ofiset portion may be forced into said space so that the final tube wall at the welded portions may be substantially of the same thickness as the gage of the stock or skelp.

The accompanying drawings illustrate apparatus adapted for carrying out my invention, wherein Fig. l isa plan view of exemplary apparatus, showing the parts of the apparatus efiective in conducting the herein described method; Fig. 2 is a side view of Fig. 1; Fig. 3 is a cross section on line 3, t in Fig. 2; Fig. 4 is an enlarged section on line l, i in Fig. 1; Figs. 5, 6, and '2 are, respectively, cross sections on lines 5, 5, it, t, and l, l in Fig. i; Fig. d is an enlarged section on line 3, 8 in Fig. 1; Figs. ll, 1d, and ll are, respectively cross sections on lines i3, 9, til, it, and it, it in Fig. 8; Fig. 12 is an enlarged eross section illus== trating the welded joint, and Figs. 13, it, and 15 are similar sections illustrating successive steps in completing a welded. tube.

Similar numerals indicate corresponding parts in the several views.

The frame is provided with various pairs of rollers for the passage of a tubular metal blank or stock A. The blank A is provided with an oilset portion a, extending along one marginal portion, upon which another marginal portion 2; of the blank is to be lapped for welding said portions together. The onset portion a may be made by suitably deflecting or bending the marginal portion of the blank, either before the blank is fed into the machine, or by suitable means provided in the machine, such as disclosed in Letters Patent to me No. 1,889,414, granted Nov. 29, 1932. In the example illustrated the metal blank A having the ofiset portion 01 passes through a support 2 on the frame I, which support has a guiding member 3 which extends through the open seam c on the blank, serving to guide the latter as it travels. At a suitable distance from the support 2 is a pair of opposed peripherallygrooved rollers having a pass therebetween for the tubular blank A, the pass being of such dimension as to cause the seam c to be closed and the marginal portion b to be lapped on the offset marginal portion a as the blank travels, such as illustrated in Fig. 6. The roller d is shown provided. with a central annular rib 5 adapted to radially oppose the ofiset portion a of the blank, as well as to oppose the inset portion a and the marginal edge b of the blank circumferentially, to cause proper alignment and registration of the lapped portions, with the edge I) suit.- ably spaced-from the inset portion a, (Figs. 6 w and 12). Within the blank A is a roll I to bear against the latter in opposition to the roller 4, the roll 1 having a peripheral groove la receiving the ofiset portion a of the blank, and serving to guide the blank in the desired position. The pass between the rollers 4, 5, the ribs, and the groove la of roller 1 cooperate to maintain the inset portion a and the edge I) of the blank in spaced relation as the blank travels. The roll I is shown engaged by a roll 8 within the blank to thrust against roller 5 with the blank interposed, whereby the desired pressure against the: blank in various directions is afforded. The rolls '4 and 8 are pivotally carried by a suitable frame 9 connected with a tubular arm it within the blank, the arm being supported by the member 3. Through an inlet tube H the am it may be supplied with water'dor cooling the parts Within the blank, in a known way. The rollers 4! and 5 are carried by shafts jourhaled in supports i2 on frame l, and said rollers may be operated by suitable gearing, at i3, 54, whereby said. rollers may serve to propel the blank A through the machine, in the direction of the arrow :c in Fig. 2.

spaced from the rollers 4, E are a pair of spaced g rollers IS, IS having peripheral grooves providing a pass to receive the blank A having the lapped marginal portions a, 17. Within the blank A are opposing rolls ll, I8, pivotally carried by a frame l9 connected with arm ID. The roll ll has a peripheral groove Ha receiving the offset portion a of the blank, thereby serving to guide the latter. The roller l5 and roll serve to compress the overlapped blank portions a and b to a predetermined or definite thickness as the tubular blank traverses between said roller and roll, as in a manner set forth in Letters Patent to me No. 1,865,531, granted July 5, 1932. The rollers I5 and I6 are journaled on supports l9 on frame I At a suitable distance from the rollers l5 and I6 are a pair of spaced electrodes and 2|, shown having grooved peripheries, to receive and bear on the blank A, respectively on opposite sides of the lapped portions 11 and b, (Fig. 9). The electrodes may be suitably spaced apart by insulation, such as at 22. The electrodes are rotative, and may be supplied with electric current in any desired way. As illustrated, the electrodes are carried by a rotary-type transformer, indicated at 23, of a well known variety, such as set forth in Letters Patent to me No. 1,594,891, granted August 3, 1926. The electrodes may be secured together and to the transformer in parallel relation, with their axes in common, as by insulated screws at 24, (Fig. 2). Any suitable guiding means for the blank A, at the electrodes, may be provided, such as rollers and 26 pivotally carried by blocks 21 and 28, supported by frame I, and adjustable by means of screws 29. The rollers 25, 26 are suitably grooved, whereby a pass or throat for blank A is provided between the electrodes and said rollers, in a known way. Within blank A is a roller 30 having a peripheral groove 30a to receive and guide the offset a of the blank, the portions of the roll at the sides of groove 30a preferably being of such diameter as not to engage the tube blank A. The roll 30 is pivotally carried by a frame 3|, connected with arm l0 within the blank, and a roll 32 is pivotally carried by said frame to bear against the bottom portion of blank A, to resist thrust of electrode 2| through roll 30, (Fig. 9). The throat between the electrodes and the rollers 25, 26 and the groove in roll 30 receiving the offset a cooperate in maintaining the inset portion a and the edge b of the tubular blank in spaced relation during welding. By preference the vertical plane through the axis of roll 30 is at one side of a plane through the axes of the electrodes 2|, 22 for a suitable distance, in the direction of travel of the blank A, and the top portion of roll 30 is slightly above the plane of the bottom surface of offset a of blank A, where it advances toward the electrodes, (Fig. 8), whereby an upward pressure of the blank against the electrodes is effected. By such means the lapped portions :1 and b are pressed together into contact for welding during the time the electric current is passing through said lapped portions between the electrodes, at which time the lapped portions adjacent to the electrodes are heated to a welding temperature by reason of the resistance between them to the flow of the current, and the offset portion a and the lapped portion b of the blank are welded. The weld between the portions a and b is effected at seam d, Fig. 12.

When the marginal portions a and b are lapped, as at the position shown in Fig. 6. the inner edge I) of the lapping portion b is set at a distance from the marginal inset portion of the blank at a, providing a space therebetween, at e, in radial register with the offset portion a, (Fig. 12), so that the said inner edge 2) will not be welded to the inset portion a, and the offset portion a protrudes inwardly within the tubular, blank. The inset portion a and the edge I) are preferably inclined or beveled in such a way as to provide their surfaces at an oblique angle with the wide part of the space 2 extending outwardly. After the welding, (as in Fig. 12) I bend the metal of the blank adjacent to the welding by pressing the offset por- 10 tion a, thereby widening the space e, and forcing the portion a into such space, whereby the seam at d is gradually turned from the substantially circular position of Fig. 12 into a position at an angle to a radius of the tube by succeeding stages 15 until the final desired position of the metal is attained, such as diagrammatically illustrated by the several steps in Figs. 13, 14, and 15. The welded and adjacent parts of the blank then assume a substantially tubular form and the offset 20 portion a, as such, disappears and becomes a portion of the tube wall. During such operations the metal adjacent to and at the sides of the weld d moves in opposite directions to accommodate the interposition of the offset metal a, (Fig. 15), which is facilitated by the oblique angular shape of the space e.

To bend the metal as aforesaid a pair of op-. posed spaced rollers 33, 34 are spaced from the electrodes, in the direction of travel of the welded so tube, said rollers having grooved peripheries providing a pass for the tube, with the welded por tion opposing the roller 33, (Figs. 8 and 10) The rollers are journaled on a support 35 carried by frame I. Within the tube is a roll 36 to engage 35 the tube at the welded portion along the offset a, which roll is carried by a frame 31 connected with the arm l0, and at 38 is a roll in engagement with the roll 36 and with the inner wall of the tube. The rolls 36, 38 take the thrust against 40 the tube between the rollers 33 and 34. The rollers 33 and 34 may be operated by gearing at 39, 40, (Fig. 1). When the welded portion of the tube arrives at roller 33 and roll 36 the offset portion a is caused to be crowded and pressed there- 5 between, with the effect of simultaneously pressing said portion a outwardly into the space e between adjacent portions of the metal of the tube and causing displacement of the side walls of the tube, gradually deforming the welded seam portion and rounding it to substantially circular form, as in Fig. 15. The throat or pass between the rollers 33 and 34 is of a somewhat oval shape, so as not to hug or resist movement of the side walls of the tube and to cause spreading of the space e to admit the offset portion a due to the pressure at the weld between roller 33 and roll 35, whereby the tube may spread as required during the bending of the welded portions as the offset portion a is forced outwardly, (Fig. 10).

Spaced from the rollers 33, 34 is a pair of spaced peripherally grooved feeding rollers 4|,

y 42, having a pass between them of circular form,

the shafts of said rollers being journaled in supports 43 on frame I. Gearing 44, 40 serves to rotate the rollers 4|, 42 for feeding the welded tube. The circular shape of the pass between the rollers 4|, 42 closely encircles and compresses the welded tube into circular form, with the seam d at an angle to a radius of the tube, (Fig. 11).

In accordance with my invention an offset marginal portion and another marginal portion of a tubular blank may be overlapped without engagement of the edge of the latter portion with the motel-oi the leaving space into Which, alter sold portions hove haeo Welded, the ofiset portion may he ioreed to become at portion oi well of the finished tohe whereby a cor responding amount of materiel is sewed ior tiihe of given diameter,

Having now descrihed my loventioo whet ll between the looping portions lying sohstohtiolly I in o oheulor direction longitudinal oi the and pressing: the offset por tion into said spooe with sold seem es'tondiogot om angle to o. radios oi sold tuholor The method or welding the por tio'os o1? o. toholor metal oloril: heaving an inset portion and on ofiset portion eomprisirig trov-= ersiog the lolehlz. lapping the oil-set portion sod another portion of the motel together with o speoe between. the edge or the lost nomad per time and the nset portion, mointeim'og said edge and sold inset portion in spaced role-lion as the hloolr travels, welding said lapped portions to gather with sold edge and said inset portion out of engagement, sod pressing the welded portions into sold spacer 3. The method of Welding the more-moi por= tioos of a, tubular metolhlonls lie-vine; an inset portion and on ofiset portion comprising trov= ersing the blank, lapping the ofiset portion and smother portion of the metal together with a,

space hetweeri the edge of the lost loo-med per time and the inset portion, mointoioiog' said edge and inset portion in spseed relotioo es the hle-oir tmv'elsr welding sold lapped portion-s together sold edge and said out of, engagement pressing the welded portions into sdid some and disploeihg the side walls orthe welded tube as the welded portion enters sad spooeu d, The method of welding the marginal por= tioos oi a tubular metsl loloolr her ing an inset portion and on ofiset portion comprising trov ersiog the h, looping the ofimt portion and another portion of the metal together with a space having surfsoes at so oblique single to one another between the edge of the lost named por= tlon and the inset portion maintaining said edge hleolz irovels, welding said looped portions to-= gether with sold edge and solid. inset out of en= sold spooe.

5c The herein described method of joining meiol morgmsilp' comprising vvel to one portion or" metal another marginal por lion offset and lapped therewith in the region of looping, while leaving so interval between the opposed edges presented to eoch other by the 1 oiiset looping? and forcing metal of the offset portion into the sold interval to fill the some:

6. The herein described method of joining mete-l marginally comprising welding to one i memo-sol portion of metal another marginal por= tloo ofi'set and lapped therewith in the region of the lapping, while leaving an interval between. the opposed edges presented to each other hr the oiiset lapping, exerting upon the welded res 'giori forces tending to increase the width of the said interval sod iorcing the metal of the ofiset marginal portion into the interval to fill thesame.

7, The herein described method of joining the morgiool portions of a tubular metal blank comprising Welg to one marginal portion of said lolonlr another marginal portion oilset and lapped therewith in the region of the lapping, while leaving on interval between the opposed edges presented to each other hy the ofiset lapping, 3 end forcing the metal of the offset marginal portion into said interval to fill the some.

8. The herein described method of joining metal marginally comprising welding to one marginal portion of metal another marginal portion odset and lapped therewith in the region of looping, while leaving an interval between the opposed edges presented to each other by the ofiset looping, sold edges so opposed lacing conve'rgeotly inclined to said offset forcing the metal of the ofiset marginal portion into the said interval to fill the some.

d. The herein described method of joining the marginal portions oi a, tubular metal blank comprising; welding in the region of their lapping one marginal portion of said blank and another msrgiool portion offset and lapped in its offset region with the first portion, while leaving an interval between the opposed edges presented to portion, and 49 each otherby the offset lapping, said edges so 53 opposed loelng convergently inclined to said oilset portion, and forcing the metal of the offset portion into said interval to fill the same. 

